This invention relates to machine tooling and, in particular, to fixturing used to support an object undergoing one or more steps in a manufacturing process. The invention is particularly adapted for supporting a component undergoing quality control inspection by a computerized measuring machine (CMM), but may also find application in supporting objects undergoing light to moderate manufacturing processing, such as assembling, soldering, laser- and water-jet cutting, welding, light-machining, and the like.
Support fixtures for objects undergoing manufacturing operations have, in the past, been provided in the form of custom-built fixtures which are capable of supporting only one object, or a series of related objects, for one or more steps in a manufacturing process. When the particular object is not in production, the fixture must be stored for possible use at a later date. Whenever a new component is introduced, or an old component substantially redesigned, a new custom fixture must be designed and built. Not only does this result in an ongoing expenditure for fixturing, but requires an ever-increasing facility to store the fixtures. Furthermore, the fixture is typically designed and built by persons who will not actually use the fixture and modifications to the fixture, once completed, are either difficult or not possible. Therefore, results are not always satisfactory.
Various attempts have been made at modular fixtures in order to overcome such deficiencies. Modular fixturing includes providing a series of components which may be interconnected in a virtually infinite number of ways in order to allow a particular fixture to be disassembled and the components reused in a different fixture configuration. Various techniques are known for recording the configuration of the components for each fixture such that a fixture may be reconstructed in the future when needed.
Modular fixtures that have been proposed have not been without their own difficulties. One type of modular fixture utilizes a vacuum source in order to retain objects on the fixture. Not only is such system expensive, it is prone to failure, especially when supporting parts in a vertical orientation, and is not useful at supporting all types of objects. Another modular system, which is made up of unique manufactured components, operates reasonably well. However, the manufactured components are built to close tolerances and are exceptionally expensive to produce. While this system is useful in supporting small objects, the nature of its components requires a large number of components to support large objects, such as fenders of vehicles, vehicle door panels, and the like with sufficient rigidity.
There is a need for a modular fixturing system which is capable of providing exceptional flexibility in the design and construction of object support fixtures. Such system should be capable of supporting objects, even large objects, in any orientation that is most advantageous to the manufacturing process. For example, vehicle side panels, such as fenders and door panels, must be supported in their vertical orientation during CMM inspection in order to avoid deviations resulting from the force of gravity on the object. Such modular fixturing system must additionally be inexpensive to produce without requiring precision manufacturing tolerances of the components making up the system.